Printing apparatus

Abstract

A printing apparatus includes a printing portion for printing on a medium, a driving roller for transporting the medium, a first and a second driven roller which are respectively supported with a gap in one roller shaft in a shaft line direction of the roller shaft and rotate around the roller shaft while pressing the transported medium on the driving roller, and a shaft support member that has a shaft support portion which supports the roller shaft between the first driven roller and the second driven roller. The first and the second driven roller have a through hole into which the roller shaft is inserted and an inner diameter in a roller center portion is smaller than an inner diameter of a roller end portion in the shaft line direction. The roller shaft is supported so as to be swingable with the shaft support portion as a support point.

What is claimed is: 
     
       1. A printing apparatus comprising:
 a printing portion for printing on a medium; 
 a driving roller for transporting the medium to the printing portion; 
 a first driven roller and a second driven roller which are respectively supported with a gap in one roller shaft in a shaft line direction of the roller shaft and rotate around the roller shaft while pressing the transported medium on the driving roller; and 
 a shaft support member that has a shaft support portion which supports the roller shaft between the first driven roller and the second driven roller, 
 wherein the first driven roller and the second driven roller have a through hole into which the roller shaft is inserted and in which an inner diameter in a roller center portion is smaller than an inner diameter of a roller end portion in the shaft line direction, and 
 wherein the roller shaft is supported so as to be laterally swingable with the shaft support portion as a support point. 
 
     
     
       2. The printing apparatus according to  claim 1 ,
 wherein the shaft support portion of the shaft support member is a bearing surface which is able to contact a side surface of the roller shaft and has a gap with the side surface of the roller shaft. 
 
     
     
       3. The printing apparatus according to  claim 1 ,
 wherein in at least one of the first driven roller and the second driven roller, the roller center portion in the through hole is a cylindrical surface which is able to contact the side surface of the roller shaft and has a gap with the side surface of the roller shaft. 
 
     
     
       4. The printing apparatus according to  claim 1 ,
 wherein in one roller shaft, a shaft part which is supported by the shaft support portion of the shaft support member is thicker than a shaft part which rotatably supports the first driven roller and the second driven roller. 
 
     
     
       5. The printing apparatus according to  claim 1 ,
 wherein the shaft support member includes a guide groove that movably guides at least one shaft end portion out of both shaft end portions of the one roller shaft along a pressing direction in which the first driven roller and the second driven roller press the medium on the driving roller.